Photoluminescence-excitation spectroscopy of porous silicon

Abstract
We have carried out photoluminescence-excitation spectroscopy (PLE) of porous silicon at different temperatures (90–300 K) for various photoluminescence emission (PL) energies (1.65–2.48 eV). Temperature-dependent PLE results indicate that there are two different processes which contribute to the PL emission. Emission at energies >2.0 eV is mainly due to a homogeneously broadened intrinsic mechanism while the lower-energy emission is from carriers confined in disorder-induced states in nanometer-sized silicon structures.